Some puzzles in the microscopic structure of the stroma

The mammalian corneal stroma has some intriguing features related to its lamellar structure. OPTICAL LAMINATION: Stromal sections under the polarizing microscope show birefringent bands that are about 5 times less numerous than the collagenous lamellae seen in transmission electron microscopy (TEM). Scattered light reveals similar laminae in the intact fresh tissue. COHESION: Very thin sections of stroma do not fall apart under water, indicating the presence of a structural framework that holds the collagen fibrils together. SHEAR DISTORTION: The stroma shears very readily in its plane; the shear amplitude increases and then decreases as the tissue hydrates. This suggests that the structural framework is coiled at physiological hydration and can expand about 10 times. FOLDING: When the stroma swells, the lamellae are thrown into waves that lie both in the plane of and perpendicular to its surface. It is difficult to understand how the latter are packed.     

Phenotypic differences in survival to an experimental acute carbon monoxide intoxication

Male and female 45-day-old mice of two inbred (CBA and C57B1) and of one outbred (OF₁), SPF (specific pathogen free), strains, LD_12:12 (L = 150 lx) synchronized, were submitted to an acute carbon monoxide challenge giving an overall survival close to 50%. Under these conditions significantly (P < 0.001) less CBA survived than the two other strains. A sex-related significant (P < 0.001 difference was observed in OF₁. Strain survival differences are independent of body weights and of respiratory and displacement activity, but appear to be related to behavior reactions towards environmental stresses. These phenotypic differences are similar to previous findings obtained with these three strains of mice submitted to a 50% survival acute hypoxic hypoxia (M. Stupfel, A. Perramon, P. Merat, J. M. Faure, and H. Masse, 1979, Comp. Biochem. Physiol., 64A, 317–323).     

Reconstruction of male external genitalia with elephantiasis

The surgical rehabilitation of a patient with severely deformed and functionally disabled genitalia due to long-standing lymphedema and infection is described and illustrated. The term "elephantiasis" has been applied to such gross lesions. Appropriate surgery to the penis, scrotum, and perineum has yielded a gratifying result. The principles and techniques of the surgical approach in such an undertaking are presented and discussed.     

The need to embrace molecular profiling of tumor cells in prostate and bladder cancer.

PURPOSE: Current treatment strategies for urological cancer are still based on empirical formulae as opposed to treatment tailored for each cancer patient. To individualize treatment, the multiple molecular abnormalities within tumor cell populations needs to be mapped out. The aim of this article is to explain molecular profiling (MP) and its associated techniques so that the process is not purely seen as a research tool but as a future adjunctive measure in patient diagnosis and treatment. EXPERIMENTAL DESIGN: A Medline search of publications relating to MP of prostate and bladder cancer was carried out. A review article was written combining the relevant published literature along with the clinical and scientific experience of both centers. RESULTS: The advent of MP now provides a strategy by which these molecular abnormalities can be assessed. As well as being of diagnostic and prognostic use, these molecular profiles will identify putative molecular abnormalities within tumor cells that may be appropriate for therapeutic modulation. CONCLUSIONS: In prostate and bladder cancer, mapping out the molecular abnormalities could be translated into a valuable tool to help solve difficult issues regarding patient management decisions.     

New non-cocaine-containing topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration /= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children.     

Increased placental apoptosis in intrauterine growth restriction

OBJECTIVES: Our purpose was to investigate a possible role for apoptosis in the pathophysiologic mechanisms of intrauterine growth restriction. STUDY DESIGN: Placental samples were obtained from 43 uncomplicated third-trimester pregnancies and from 26 pregnancies complicated by intrauterine growth restriction. The definition used to identify cases of intrauterine growth restriction depended on three criteria: clinical evidence of suboptimal growth, ultrasonographic evidence of deviation from an appropriate growth percentile, and individualized birth weight ratios <10th percentile. Light microscopy was used to quantify the incidence of apoptosis. Electron microscopy and TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick end labeling) staining were used to confirm the occurrence of apoptosis. RESULTS: Quantification of apoptosis (medians and interquartile ranges) resulted in the following values: normal third trimester (n = 43) 0.14% of cells (0.08% to 0.20%) and intrauterine growth restriction third trimester (n  = 26) 0.24% of cells (0.16% to 0.29%). The incidence of apoptosis was significantly higher in placentas from pregnancies with intrauterine growth restriction compared with normal third-trimester placentas (p < 0.01, Mann Whitney U test). CONCLUSIONS: These results suggest that apoptosis may play a role in the pathophysiologic mechanisms of intrauterine growth restriction.(Am J Obstet Gynecol 1997;177:401)     

食品中明矾含量的快速测定方法

目的建立一种能简单快速检测食品中明矾含量的方法。方法采用特征离子鉴别方法定性,用Na2EDTA络合滴定方法定量。结果该方法回收率在99.0%~102.8%之间,RSD在0.91%~1.38%之间。结论方法操作简单,准确性好,适合于大批量样本检测。